Removal of soap from oxo bottoms by solid adsorbents



ilnited States Patent REMOVAL OF SOAP FROM OX0 BO'ITOMS BY SOLID ADSORBENTS Rhea N. Watts, St. Francisville, La., assignor to Esso Research and Engineering Company, a corporation of Delaware N0 Drawing. Application February 24, 1956 Serial N0. 567,447

7 Claims. (Cl. 260-643) This invention relates to the removal of certain precipitate-forming components in high boiling oxygenated organic solvents. More particularly, this invention relates to the selective removal of soap from 0x0 bottoms contaminated therewith by contact with solid adsorbents having certain physical characteristics.

OX0 bottoms which are described below are recognized as exceptional solvents for various herbicidal, fungicidal and the like compounds, such as pentachlorph'e'nol, 2,4- dichlorphenoxy acetic acid and 2,4,5 trichlorphenoxy acetic acid. One of the primary ditficulties encountered when using OX0 bottoms as a solvent for the above and similar compounds, is the formation of highly objectionable precipitates. These precipitates cause considerable trouble especially when spraying equipment is used. Precipitates of the character described above may be avoided if the OX0 bottoms are distilled extensively; however, this procedure obviously wastes a large percentage of otherwise valuable Oxo bottoms product and in most cases, the cost of such a process is prohibitive.

It has been discovered that 0x0 bottoms containing objectionable precipitate-forming soaps may be treated with certain solid adsorbents having particular pore size characteristics to selectively remove these soap contaminants.

0x0 bottoms It is now well known in the art that oxygenated organic compounds may be synthesized from olefins by a reaction of the latter with carbon monoxide and hydrogen in the presence of a catalyst containing cobalt in a two stage process to produce compounds having one more carbon atom than the starting olefinic material. The literature is rich with information regarding the various modifications of the Oxo or carbonylation process and reference may be had to Bureau of Mines publication datedJui-ie 1948, entitled Critical Review of the Chemistry ofOXo Synthesis for the Production of Alcohols from Olefins, Carbon Monoxide and Hydrogen. A typical procedure for the production of alcohols and higher molecular weight bottoms by the OXo process follows:

A O; olefin is reacted with hydrogen and carbon monoxide 1.25 to l, at 3,000 p. s. i. and 300 F. in the pi'esence of a cobalt oleate catalyst in the amount of 0.1 to 0.2 wt. percent expressed as cobalt metal. The product resulting from this first step is predominantly aldehydic but contains other oxygenated compounds including alcohols. This aldehydic product is then hydrogenated in the presence of a catalyst such as molybdenum sultide on activated char under a hydrogen pressure of 3,000 p. s. i. and a catalyst bed temperature of about 375 to 520 F. to produce the alcohols. The product resulting from this hydrogenation step is primarily C alcohols but also contains unreacted olefins particularly branch chain olefins, paraffins, esters, ethers, dimer alcohols, acetals and residual soaps from the catalyst introduced in the first step. The hydrogenated product is then distilled to separate a major portion of the C alcohols from the other components. To minimize corrosion in the distillation equipment, a caustic wash is usually employed to neutralize acids. However, this caustic wash adds more objectionable precipitate forming soap to the system. The bottoms or higher boiling cut from the distillation of the alcohol product which may comprise 15 to 30% of the entire hydrogenated product will contain the higher boiling alcohols, esters, ethers, soaps and the like. It is this bottoms out which is referred to conventionally and herein as OX0 bottoms. Bottoms from an OX0 process for the preparation of a C alcohol is referred to herein as C OX0 bottoms. A typical composition of C Oxo bottoms from a process such as described above is as follows:

Percent by weight C alcohols 10 C dimer alcohols 40 Esters 23 C16 other Soaps 2 Higher C homologues 5 C alcohols. 5-25 C dimer alcohols 1 0-40 Esters 0-40 C ether 0-20 Soaps 1 0-10 These figures will be 0 only when the caustic wash is omitted. It is to be understood that the above typical composition represents Oxo bottoms resulting from a process employing a C olefin feed. This invention is applicable also to C -C OX0 bottoms which result from the OX0 process employing C -C olefinic materials as the feed as Well as other alcoholic solvents contaminated with soaps.

Solid adsorbents In general, the chemical composition of the particular adsorbents useful for the purpose of the present invention, i. e., to selectively remove precipitate-forming soaps from OX0 bottoms, is secondary. It is only necessary, that the adsorbents contain average pore diameters of from 60 to 110 A. Typical of the adsorbents which conventionally contain average pore diameters Within the necessary range are silica-alumina cracking catalysts having a low alumina content, e. g., 5 to 25 wt. percent and 20% boria on silica-alumina (1:1). While gels of many metal oxides prepared by conventional methods and other solid adsorbents have average pore diameters too small to be of utility in this process, there are known methods of enlarging the pore diameters. These methods include steaming, slow aging processes, dehydrogenation at reduced pressures, displacing water in the set gel with butai101 and the like before drying and the addition to the gel of a third component which can be washed out after the gel is set.

Attapulgus clay. a kaolin consisting largely of alumina silicates may be treated to produce an adsorbent having approximately A. average pore diameter. The follow ing method of preparing an adsorbent having the desired pore diameter is illustrative. It is to he understood that this invention is not concerned with any particular method of preparing adsorbents, but rather with the use of adsorbents having certain physical properties.

'having the pore' diameter range recited above. amount employed, of course, willdepend upon the'amonnt of soap contained in the x0 bottoms. However, in gen mixture, percolation, etc.

Common commercial silica-alumina cracking catalysts having pore diameters within the desired range are readily available and inexpensive. Moreover, these catalysts, be-,

sides removing; soaps will break emulsions and absorb 7 small amounts of water which may be present in the OX0 bottoms; Accordingly, silica-alumina cracking catalysts are preferred as adsorbents for this process.

Example-Freshsilica alumina 87-13% having a pore I diameter of about 40 A. is treated with steam'and heat at 510 C. fora period of 24 hours, to produce a silica-alumina adsorbent having an averagepore diameter of 100 A. V

.. For a more detailed discussion'of various processes Y for preparing solid adsorbents having a pore size over about 60 A., reference is made to U. S. Patent'2, 469,314

. to Byland et al. In the above patent, general and specific V examples of regulating and calculating poresize are given,

and such disclospre is incorporated herein. It will be noted, however, that the formula in col. 4 of said patent The process of the present invention involves contacting a soap contaminatedfoxygenated solvent and especially 0x0 bottoms with very small amounts of a solid adsorbent The Average Selective Pore Complete Diameter, Soap A. 'Remova-l Activated Carbon No. Activated Alumina -s 54 No. High (40%) Alumina-Silica Cracking Catalyst 36 No. 20% Alumina-Silica Cracking Catalyst 85 "Yes. 13% Alumina-Silica Cracking Catalyst 92 Yes Filtrol 55 No. 13 A. Molecular Sieve, Lind'e;. 13 No. Silica Magnesia Cracking Catalyst 31 No. Chromia Gel; 27 No. Socony Vacuum Bead.1 3% AhOx-SiOz Cata- 50 N0;

lyst. V

a i Silica Gel 19 N0. 20% Boria Catalyst (On 50% $10 50% A110 95 Yes Attapulgus Clay- V 54 No.

era'l, from 3 to 20 lbs of adsorbent per 100 lbsrof oxo bottoms may be employed. The adsorbent is removed from the soap free OX0 bottoms by filtration, decantation. or other'similar means, 0 Regeneration of adsorbents may be accomplished by treatment with hot water and may be hastened by the addition of a low molecular weight alcohol. Contacting may be accomplished by simple adxnmple..fl00 lbs. of aC 0x0 bottoms product resulting from 'a process such as described'above and having the following typical composition was admixed with alt) lbs.

utes. analyzed as follows:

After,

B efore,

percent percent C; Alcohols Cu Dimer Alcohols 1 stars Ethers-. Soups 1 Higher C3 Homologues.;

rompen Mouse 1 Loss of alcohol was determined by hydroxyi number.

i V 2. A method in accordance with claim 1 solvent is Oxo bottoms.

VI The presence or absence of soap in the filtered sample after contact V was tested by the addition of water to show the sample and the use of a phenolphthaleln indicator to show alkali present.

0x0 bottoms, before or after'treatment, have remarkablesolvent properties. For example, pentachlorphenol was dissolved in the above untreated Oxo bottoms to form a solution. This solution aferward was diluted with diesel fuel for treating wood products to protect them against termites or fungi. "The finalconcentration of the diluted solution was 1% pentachlorphenol.

When untreated Oxo bottoms were employed as the solvent, an

objectionable precipitate formed which was sufiicient'to cause considerable clogging in spray equipment. The

same solution was made up with the treated Oxo bottoms and no precipitate resulted. To show that the selective soap removal qualities ofthe adsorbents tested were attributable to the particular pore diameter, Oxo bottoms were contacted with the following adsorbents:

of which have averagepore diameters below about56 A a V removed desirable dimer alcohols from the OX0 bottoms. It is to be understood that the present process may .be applied to alcoholcontaining solventsother than Oxo-bot-. toms wherein saidjsolvents are'contaminated with precipi tate forming soaps. H i whatisclaimedis: j v j 1 l. A method of treating an oxygenated solvent containing alcohol as a principal/component, said solvent being n am e w a m nqnamo nt prec i em soap which comprises contacting. said solvent-with a solid adsorbent having an average-pore diameter between about j swe n 60-110 A. to selectively'adsorb said soap and the soap free solvent from the adsorbent. V I

wherein said 7 '3; A meth'odfin accordance with claim 1.whei'ein the said average pore diameter is between about to A.

4. A meth odin accordance withclaim 3 wherein from 3'to 20 lbs. ofadsorbent per l00 lbs. .of solvent arefemployed. a i

5. A method of separatingprecipitate-forming amounts of soap from 0x0 bottoms contaminatedwith said soap which comprises contacting said-contaminated Oxo bottoms with a solid absorbent having an average pore diameter of about 60 -1 10 A. to selectively adsorb said soap therefromand separating the soap free Oxo bottoms from the adsorbent: '6. A method in accordance with claim f5-wherein said solvent is C Oxo bottoms. V 7.- A method in accordancewith claim 6 wherein said adsorbent is silica-alumina. i

References Cited in: the file ofthis patent V UNITED STATES PATENTS; j

ormza REFERENCES a. r v Drake et al.:' Ind. Eng: Chem. (Anal-(Edit), vol. 17 (194 P-'782.91. 1' if 

1. A METHOD OF TREATING AN OXYGENATED SOLVENT CONTAINING ALCOHOL AS A PRINCIPAL COMPONENT, SAID SOLVENT BEING CONTAMINATED WITH A MINOR AMOUNT OF PRECIPITATE-FORMING SOAP WHICH COMPRISES CONTACTING SAID SOLVENT WITH A SOLID ADSORBENT HAVING AN AVERAGE PORE DIAMETER BETWEEN ABOUT 60-110 A. TO SELECTIVELY ADSORB SAID SOAP AND SEPARATING THE SOAP FREE SOLVENT FROM THE ADSORBENT. 